TopQuark

Well, it happened to me too. The idle cycles between 2000 to 3000 rpm and it turns out, the throttle unit was not mounted correctly. The throttle spring that opens and close the valve is not seated correctly. I can tell by the gas pedal. It feels light and does not engage well. As stated by ml30306 in post# 170, if you want to replace the 3 screws for the throttle unit for the RX300, get 2 units with bolt size M6 with 1" pitch and length of 60mm and another one with size M6 and length of 28 mm also with 1" pitch. Diameter of the screws is ~5mm. I did not replace any of the gaskets and O-rings.

Ah! That's it. Thanks.

My transmission failed the other day. The reverse gear does not work. The engine runs but reverse seems it is in neutral. I replaced the 2 speed sensors but did not help. This weekend, I am going to drop the pan, drain, and replace the ATF. I only have 50,000+ miles in my RX. I am getting ready to replace the transmission. I read somewhere that 2001 and up Highlanders uses the same U140F transmission. I can replace my transmission with the Highlander and can shave half the price I will pay on a Lexus brand. Has anyone tried this? Is the RX300 transmission fully compatible with Toyota Highlander like a plug and play?